In some applications light fixtures having high aspect ratios, i.e., having length and width which are much greater than their thickness, are desirable. For example, automotive taillights are preferably designed to be as thin as possible because volume required for such space typically comes at the expense of luggage area.
One approach to producing such high aspect ratio light fixtures is described in U.S. Pat. application Ser. No. 016,858, field Feb. 20, 1987, now U.S. Pat. No. 4,789,921 and commonly assigned herewith. One system of that application, a Fresnel type reflector imitates the action of a parabolic reflector when it is formed into a cone. Such a reflector provides a higher aspect ratio than is possible with a standard smooth parabolic reflector, but has greater light gathering efficiency than a flat Fresnel type reflector.
Another approach is described in U.S. Pat. application Ser. No. 030,033, filed Mar. 24, 1987, now U.S. Pat. No. 4,799,157 and also commonly assigned herewith. In the approach of application Ser. No. 030,033, a special reflective film is prepared which reflects light at a right angle to the direction from which the light enters the film. Such a film is used to direct light out of the light fixture.